Improvement in devices for overcoming the dead-centers of cranks



T. L. HUBBARD.

DEVICES FOR OVERCUMING THE DEAD-CENTRES OF CRA-ITKS.

No.178,150. Patented. MayBO, 1876.

N. PETERS. PHOTCHJTHOGRAPHER, WASHINGTOP, D c.

UNTTED STATES PATENT Orrrono THEODORE L. HUBBARD, OF PORT HURON, MICHIGAN.

lMPROVEMENT IN DEVICES FOR OVERCOMING THE DEAD-CENTERS 0F CRANKS.

Specification forming part of Letters Patent No. 178,150, dated May 30, 1876; application filed December 24, 1875. i

To all whom it may concern Be it known that I, THEODORE L.HUB- BARD, ,of Port Huron, in the county of St. Clair and State of Michigan, have invented a Device for Overcoming the Dead-Centers of Cranks, of which the following is a specification:

My invention has for its object to provide a means for overcoming the dead-centers of cranks, and is more especially adapted to and applicable in the colwersion of reciprocating into rotary motion, in which case it takes the form of a peculiar connection of the pitman to the crank-disk, consisting of a leaf-sprin g eccentrically secured at one end to a bracket on the faceplate, the free end having an eye, which receives a wrist on the pitman, which eye end plays between two socket-lugs projecting from the face-plate in the radius of the spring, as more fully hereinafter set forth.

Figures 1 and 2 are perspective views, showing different positions of the crank and pit man. Fig. 3 is a cross-section of the pitman, Wrist, and spring.

In the drawing, A represents a face-plate or crank-disk, to be rotated by a reciprocating pitman, B, at the end of which is a wrist, a, journaled in an eye, I), at the free end of a leaf-spring, (J, whose other end is rigidly secured in a bracket, 0, placed near the periphcry of the face-plate, in such a position that the leaf-spring will take the direction of a chord (other than a diameter) across the said face-plate. 'lwo concave or socket lugs, d d, limiting the curvilinear movement of the free end of the leaf-spring, project from thefa-corest in and exert a propelling strain upon lug d until just before the back center is reached, when it will move out of the said socket. The pressure of the pitman being still in the same direction, a tensile strain is put by it upon the spring whose connection to the face-plate (the bracket) being above the line of centers, the motion of the face-plate is continued thereby until the pitman commences the'ret-urn movement, when the spring will yield, and the eye I) will jump back into the socket-lug (I, now some distance below the line of centers, and act upon it to rotate the face-plate until the other center is approached, when the action will be the reverse of that just described.

' What I claim as my invention is-- The spring and socket lugs, secured to the face of a crank-disk, substantially as described, in combination with the wrist on the pitman, journaled in an eye at the free end of said spring, substantially as and for the purpose set forth.

THEODORE L. HUBBARD. Witnesses:

JAMES G. BRIGHT,

ANNA MOKAY,

NELLIE MOKAY. 

